War-shocked, Marco is haunted by his recurring, disturbing dreams of Shaw calmly murdering two members of their platoon. Moreover, his position as Public Relations Officer has been a disaster. Marco defends himself to his Colonel - he suspects that the honor awarded Shaw was a sham:

I tell ya, there's something phony going on. There's something phony about me, about Raymond Shaw, about the whole Medal of Honor business...I said: 'Raymond Shaw is the kindest, warmest, bravest, most wonderful human being I've ever known in my life, and even now I feel that way - this minute. And yet, somewhere in the back of my mind, something tells me it's not true. It's just not true. It isn't as if Raymond's hard to like. He's IMPOSSIBLE to like. In fact, he's probably one of the most repulsive human beings I've ever known in my whole - all of my life.

Marco's commanding officer orders him to be placed on forced, "indefinite sick leave."

In the parlor car of a New York-bound train - on the way to seek the truth about Shaw - Marco, who is sweating profusely and trembling, is seated next to a beguiling, mysterious, attractive Rosie Chaney (Janet Leigh). He cannot light his cigarette due to his shaking hands. Embarrassed, he hurriedly gets up, tips over a table with his drink on it, and flees to the space between the train cars. She follows him to befriend him, and then lights a cigarette for him and taps him on the shoulder to offer it to him.

Herein begins an intriguing, off-the-wall scene - filmed almost entirely as a two-shot without cuts - in which she is the aggressor and he passively half-listens while self-absorbed by his own problems. During their weird, oblique conversation [taken directly from Condon's novel], they talk about four US states, Columbus' football team, railroad lines, and her two names (Eugenie and nickname Rosie) - are they speaking in cryptic code? [Is Marco also brainwashed as a Manchurian pawn - and is Chaney his controlling operative? And is the beguiling Rosie another agent?]

Rosie: Maryland's a beautiful state.
Marco: (Looking away) This is Delaware.
Rosie: I know. I was one of the original Chinese workmen who laid the track on this stretch. But nonetheless, Maryland is a beautiful state. So is Ohio, for that matter. (She lights her own cigarette.)
Marco: I guess so. Columbus is a tremendous football town. You in the railroad business?
Rosie: Not anymore. However, if you will permit me to point out, when you ask that question you really should say, 'Are you in the railroad line?' Where's your home?
Marco: I'm in the Army. I'm a major. I've been in the Army most of my life. We move a good deal. I was born in New Hampshire.
Rosie: I went to a girls' camp once on Lake Francis.
Marco: That's pretty far north.
Rosie: Yeah.
Marco: What's your name?
Rosie: Eugenie.
Marco: (He finally looks at her) Pardon?
Rosie: No kidding, I really mean it. Crazy French pronunciation and all.
Marco: (He looks away) It's pretty.
Rosie: Well, thank you.
Marco: I guess your friends call you Jenny.
Rosie: Not yet they haven't, for which I am deeply grateful. But you may call me Jenny.
Marco: What do your friends call you?
Rosie: Rosie.
Marco: (He looks at her) Why?
Rosie: My full name is Eugenie Rose. (He looks away) Of the two names, I've always favored Rosie because it smells of brown soap and beer. Eugenie is somehow more fragile.
Marco: Still, when I asked you what your name was, you said it was Eugenie.
Rosie: It's quite possible I was feeling more or less fragile at that instant.
Marco: I could never figure out what that phrase meant: more or less. (He looks at her) You Arabic?
Rosie: No.
Marco: (He reaches to shake her hand) My name is Ben, really Bennett. Named after Arnold Bennett.
Rosie: The writer?
Marco: No, a lieutenant colonel who was my father's commanding officer at the time.
Rosie: What's your last name?
Marco: Marco.
Rosie: Major Marco. Are you Arabic?
Marco: No, no.
Rosie: Let me put it another way. Are you married?
Marco: No. You?
Rosie: No.
Marco: What's your last name?
Rosie: Chaney. I'm a production assistant for a man named Justin, who had two hits last season. I live on 54th Street, a few doors from the modern museum of art, of which I'm a tea-privileges member, no cream. I live at 53 West 54th Street, Apartment 3B. Can you remember that?
Marco: Yes.
Rosie: ELdorado 5-9970. Can you remember that?
Marco: Yes.
Rosie: Are you stationed in New York? Or is stationed the right word?
Marco: I'm not exactly stationed in New York. I was stationed in Washington, but I got sick, and now I'm on leave, and I'm going to spend it in New York.
Rosie: ELdorado 5-9970.
Marco: I'm gonna look up an old friend of mine who's a newspaper man. We were in Korea together.

The scene shifts to the interior of Shaw's apartment, where Chunjin, an "Oriental gentleman" who served with Shaw in the Army, is ushered in. Supposedly, Shaw's step-father provided Chunjin with a visa so that he could come to America to find employment as a servant: "I am tailor and mender, I am cook, I drive car...I fix anything, I take message." Although the loathsome Shaw doesn't want to hire Chunjin ("Job?...but my dear fellow, we don't need interpreters here - we all speak the same language"), the man is hired as Shaw's valet for $60/week, with "every Thursday and every other Sunday off."

Senator Iselin is reflected off the glass covering a portrait of Lincoln - juxtaposing the ghostly-thin, anti-Communist with a stalwart American from another era, as he fixes himself a drink. As a spineless puppet, Senator Iselin complains to his wife that he can't keep the number of Communists straight in the Defense Department: "I mean, the way you keep changing the figures on me all the time. It makes me look like some kind of a nut, like an idiot." She holds up a newspaper and proclaims:

Well, you're going to look like an even bigger idiot if you don't get in there and do exactly what you're told...Who are they writing about all over this country and what are they saying? Are they saying: 'Are there any Communists in the Defense Department?' No, of course not, they're saying: 'How many Communists are there in the Defense Department?' So just stop talking like an expert all of a sudden and get out there and say what you're supposed to say.

When he crumples, she apologizes for being dictatorial and brash: "Would it really make it easier for you if we settled on just one number?" As he pumps Heinz [commonly known as 57 Varieties] tomato ketchup from a bottle onto his steak, she arbitrarily decides on the exact number of card-carrying members of the Communist Party in the Defense Department for his script - so it will be easy for him to remember. [This is one of the film's most amusing jokes.] In Iselin's speech to the Senate later that afternoon in the next cut, he accuses the Defense Department of hiring '57' members of the Communist Party.

When Marco rings the bell on Raymond Shaw's apartment door, the new valet Chunjin answers the door. Instantly, he is face-to-face - in a tight closeup - with someone he recognizes from the deep recesses of his consciousness, and he remembers more of his repressed memories. This was the man that led the platoon into an ambush. He punches him and they engage in a vicious, wild, martial arts/karate fight with eye gouging and rib kicking. [It has been noted as the first karate fight on film.] Marco shouts out questions:

• "What was Raymond doing with his hands?"
• "How did the old ladies turn into Russians?"
• "What were you doing there?"

[During the fight, a painful grimace on Sinatra's face was caused when he smashed his hand on the wooden coffee table, and broke the little finger on his left hand.] The noise of the fight - symbolic of American conflict with Asia - alerts nearby neighbors to call the police. Marco is detained and taken to the 24th precinct of the Police Department. After remembering Rosie's phone number, he calls her. She meets him in the police station and he is released into her custody - as a Puerto Rican cop speaks Spanish on the phone behind them.

In a taxi as she tends to his facial wounds, she divulges that she is engaged ("I told you I wasn't married. I never said I wasn't engaged"), although after meeting Marco on the train and returning home, she describes how she instantly called off her engagement to her fiancee. In a bizarre, intriguing conversation, she defines their strong bond, while confusing the capital city with the name of one of its most famous generals:

...You were a pretty solid type yourself, according to Washington - with whom they had apparently checked. So I figured if they were willing to go to all the trouble to get a comment on you out of George Washington, why - you must be somebody very important indeed. And I must say it was rather sweet of the General with you only a Major. I didn't even know you knew him. If they were the tiniest bit puzzled about you, they could have asked me. Oh yes, indeed, my darling Ben. They could have asked me and I would have told them. (They kiss each other.)

Later at Raymond's apartment, Shaw is furious that his war comrade broke into his apartment and beat up his houseboy. When Marco mentions his awful "real swinger of a nightmare," Shaw interrupts: "Is it about a Russian general and some Chinese and me and the men who were on the patrol?" Shaw continues to describe the contradictory letter from Corporal Melvin about how Shaw was "the best friend he had in the Army" - very different in mood from how all the men in the platoon really felt about their Sergeant: "You know how much the guys in the outfit hated me. Well, not as much as I hated them, of course." The nightmare of the patrol sitting together in the hotel lobby with "a lot of Chinese brass and Russian generals" is the same one that Marco has been experiencing.

On a hunch based on his suspicions (that his dreams are flashbacks to his troop's capture in Korea) as he pieces the puzzle together, Marco travels to Washington to watch projected photographs of "male models, Mexican circus performers, Czech research chemists, Japanese criminals, French head waiters, Turkish wrestlers, pastoral psychiatrists, and of course, various officials of the USSR, the People's Republic of China and the Soviet Army." In the test of recognition, Marco halts the screening on shots of two individuals who were in his dreams (and in the audience during the brainwashing demonstration). According to Marco, one of them, Berezovo (Madame Spivy), a member of the Central Committee "wore sunglasses and smelled like a goat." Remarkably, Corporal Melvin made identical identifications one hour earlier in Alaska. Having convinced Army Intelligence that he isn't insane, Marco is put in charge of a combined government intelligence unit (a CIA and FBI joint force) based in New York to work on the mystery - his assignment is to investigate Raymond Shaw and his activities.

Over bottles of champagne on Christmas Eve shared with Marco while a record plays "The Twelve Days of Christmas," Shaw describes his unhappy childhood under the dominance of his demagogue, icy mother:

My mother, Ben, is a terrible woman. A terrible, terrible woman...You know, Ben, it's a terrible thing to hate your mother. But I didn't always hate her. When I was a child, I only kind of disliked her. But after what she did to Jocie and me, that's when I began to hate her...Jocie Jordan - Senator Jordan's daughter...Thomas Jordan's daughter and Johnny Iselin's step-son...Years later, I realized, Ben, that I am not very loveable...Some people are loveable and some people are not loveable. I am not loveable. Oh, but I was very loveable with Jocie. Ben, you can't believe how loveable I was.

As he drinks, he recollects how his emasculating mother "fixed all that." In a flashback scene at the edge of a lake near his summer residence (just before Shaw went into the army), a beautiful blonde named Jocelyn Jordan (Leslie Parrish) unexpectedly appears with a razor-blade in her hand to help open up a snakebit wound on Raymond's leg. Unintentionally provocative, she removes her white blouse to make an emergency tourniquet. Her father, Senator Thomas Jordan (John McGiver), who stands in front of a gigantic gilded American eagle, has no love for Raymond's mother, his arch-enemy. She once slandered him on a network radio program: "I once found it necessary to sue your mother for defamation of character and slander...One of your mother's more endearing traits is her tendency to refer to anyone who disagrees with her about anything as a Communist." During that idyllic summer, Raymond fell in love:

You just cannot believe, Ben, how loveable the whole damn thing was. All summer long, we were together. I was loveable, Jocie was loveable, the Senator was loveable, the days were loveable, the nights were loveable, and everybody was loveable - except, of course, my mother.

Raymond's vicious, overly-smothering mother - sitting next to a bust of Lincoln and in front of a fireplace portrait of Lincoln - sabotages his relationship and potential marriage plans with the daughter of one of his step-father's political foes - she labels Jocie "a Communist tart." She interprets his romance as dangerous to her own plans, and maternally 'brainwashes' him to give her up:

Raymond, if we were at war, and you were suddenly to become infatuated with the daughter of a Russian agent, wouldn't you expect me to come to you and object, and beg you to stop the entire thing before it was too late? Well we are at war. It's a Cold War, but it will get worse and worse until every man, woman, and child in this country will have to stand up and be counted, to say whether they are on the side of right and freedom or on the side of the Thomas Jordans of this country. I will go with you to Washington, tomorrow if you like, and I will show you documented proof that this man stands for evil, that he is evil, and that his whole life is devoted to undermining everything that you and I and Johnny, and every freedom-minded American...

In a futile effort, Raymond covers his ears with his hands to drown out the diatribes of his mother, a person he intensely hates. "She won, of course. She always does. I could never beat her. I still can't," Raymond whimpers when the scene returns to the present: "I'm not loveable. But I loved her. I did love her. I do love her."

The next day, Raymond enters Jillys, a New York City bar [owned by Frank Sinatra's friend Jilly Rizzo]. The bartender, in a story being told to other customers - advises - with the triggering phrase:

Why don't you pass the time by playing a little solitaire?

This prompts a conditioned response in Shaw, who begins playing cards until he turns over the Queen of Diamonds - just as Marco joins him. Again, Raymond's directions for action come from the coincidental conversation of the bartender:

Why don't you go and take yourself a cab and go up to Central Park and go jump in the lake?

He rushes out of the bar with Marco following close behind. Now an automated, brain-washed zombie, he proceeds in a cab to the park, walks to a boathouse and pier and jumps - in the middle of winter - into frigidly-cold water on the lake covered with ice. Marco is flabbergasted as he pulls his friend out and realizes that Raymond doesn't remember anything.